A multicenter survey on the prevalence of multiple-pharmacy use in patients prescribed specialty medications

Multiple-pharmacy use (MPU) is common, with approximately 38% of patients in the United States using 2 or more pharmacies. The current literature has not examined the prevalence of MPU among patients who use specialty medications.

This study aimed to estimate the prevalence of MPU among patients who use specialty medications.

This was a multicenter cross-sectional study across 3 medical institutions. Patients who use specialty medications for oncology, autoimmune diseases (AIDs), or multiple sclerosis (MS) were surveyed at each site. The inclusion criteria include being 18 years of age or older, being English speaking, and having a specialty medication order placed within the past 3 months. Participants were asked 11 questions assessing MPU including methods of obtaining medications and medication adherence. The primary outcome of this study was to estimate the prevalence of MPU among patients who use specialty medications. The secondary outcomes characterized other factors potentially affecting MPU and assessed the impact of MPU on medication adherence.

A total of 401 participants using specialty medications for AIDs (n = 160), MS (n = 93), and oncology (n = 148) completed the survey. A total of 327 patients (81.5%) reported using multiple pharmacies. The top 3 reasons for MPU included convenience (49.5%), insurance requirement (33.9%), and cost (11.6%). The incidence of at least 1 missed dose within the last month was 18.9% for those using 1 pharmacy and 17.4% for those using multiple pharmacies. A total of 71 patients stated why they missed a dose within the past month. The common causes were forgetfulness (52%), other (34%), and adverse effects (8.5%). Adherence did not differ between those patients who experienced MPU and those who did not.

Patients who use specialty medications have a higher prevalence of MPU than patients who do not use specialty medications. The prevalence of MPU was not associated with decreased self-reported adherence to specialty medications.